Publications by authors named "Seung Kook Park"

Green tea contains polyphenols, mainly four catechins, including (-)-epigallocatechin gallate, (-)-epicatechin gallate, (-)-epigallocatechin, and (-)-epicatechin. Enzyme tannase is known to hydrolyze gallated catechins into non-gallated catechins and gallic acid (GA). In this study, dried green tea leaves were treated with tannase to determine changes of volatile and non-volatile compounds by the hydrolysis.

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We tested the hypothesis that exaggerated pressor responses observed in prehypertensive males (N = 9) during dynamic exercise are attenuated following acute dietary supplementation with grape seed extract (GSE) (i.e., a single dose).

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Korean red pine () is one of the major species in Korea. Red pine bark is removed prior to the chipping process in the wood industry and discarded as waste. However, red pine bark contains a considerable amount of naturally occurring phenolics, including flavonoids, and therefore may have a variety of biological effects.

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Oxidative stress contributes to neurodegenerative disorders such as Alzheimer's disease. Phenolic antioxidants can efficiently reduce oxidative stress. In this study, we evaluated the effects of the freeze-drying process on phenolics, antioxidants, and cholinesterase inhibition in five cultivars of kiwifruits grown in Korea, cv.

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Quorum quenching (QQ) has recently been acknowledged to be a sustainable antifouling strategy and has been investigated widely using lab-scale membrane bioreactor (MBR) systems. This study attempted to bring this QQ-MBR closer to potential practical application. Two types of pilot-scale QQ-MBRs with QQ bacteria entrapping beads (QQ-beads) were installed and run at a wastewater treatment plant, feeding real municipal wastewater to test the systems' effectiveness for membrane fouling control and thus the amount of energy savings, even under harsh environmental conditions.

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This study was conducted to investigate the toxic metal content (Pb, As, Cd and Hg) of 52 frequently prescribed herbal medicines and to identify herbal medicines that exceed the Korea Food and Drug Administration (KFDA) maximum limits. A total of 3534 samples, including 1966 domestic samples and 1568 imported samples, were analysed using an Inductively Coupled Plasma-Mass Spectrometer (ICP-MS). Total amounts of Pb, As, Cd and Hg were significantly different between domestic (0.

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Purpose: The purpose of this study was to investigate the effectiveness of tumor necrosis factor (TNF)-α blocker for treatment of dry eye (DE)-induced inflammation and determine a more effective method to suppress lacrimal gland inflammation. Efficacy of topical versus systemic administration of TNF-α blockers was determined using a murine dry eye (DE) model.

Methods: The TNF-α blocker HL036 was developed by modification of the TNF receptor I.

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The definition of fat differs in different countries; thus whether fat is listed on food labels depends on the country. Some countries list crude fat content in the 'Fat' section on the food label, whereas other countries list total fat. In this study, three methods were used for determining fat classes and content in bakery products: the Folch method, the automated Soxhlet method, and the AOAC 996.

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The correlation between alcoholic fermentation rate, measured as carbon dioxide (CO2) evolution, and the rate of hydrogen sulfide (H2S) formation during wine production was investigated. Both rates and the resulting concentration peaks in fermentor headspace H2S were directly impacted by yeast assimilable nitrogenous compounds in the grape juice. A series of model fermentations was conducted in temperature-controlled and stirred fermentors using a complex model juice with defined concentrations of ammonium ions and/or amino acids.

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This study was conducted to evaluate the effects of vardenafil (Levitra), a phosphodiesterase-5 (PDE-5) inhibitor, on cell proliferation in the hippocampal dentate gyrus and on 5-hyroxytryptamine (5-HT, serotonin) synthesis and tryptophan hydroxylase (TPH) expression in the rat dorsal raphe nucleus. Male Sprague-Dawley rats were divided into 6 groups (n=5 in each group): a control group, a 0.5 mg/kg-1 day vardenafil-treated group, a 1 mg/kg-1 day vardenafil-treated group, a 2 mg/kg-1 day vardenafil-treated group, a 1 mg/kg-3 day vardenafil-treated group, and a 1 mg/kg-7 day vardenafil-treated group.

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A hydrogen sulfide (H2S) detecting tube was developed for the quantitative determination of H2S produced by yeast during laboratory scale wine fermentations. The detecting tube consisted of a small transparent plastic tube packed with an H2S-sensitive color-indicating medium. The packed medium changed color, with the color change progressing upward from the bottom of the tube, upon exposure to H2S produced by yeast during fermentation.

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As tea is traded all over the world, it is necessary for both customs officers and business investigators to develop an easy and reliable method to discriminate teas from each other. A total of 56 kinds of various green, Oolong, and black teas were collected from different countries and markets, and their catechin contents and volatile flavour compounds (VFC) were compared by analyses, using HPLC and solid-phase microextraction-gas chromatograph (SPME-GC). It was found that neither total catechin nor individual catechin contents in green and Oolong teas were significantly different among the samples investigated, but the fermentation processes altered the profiles of tea VFC.

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Squalene synthase plays an important role in the cholesterol biosynthetic pathway. Inhibiting this enzyme in hypercholesterolemia can lower not only plasma cholesterol but also plasma triglyceride levels. A squalene synthase inhibitor was screened from Prunus mume fruit, and then purified via sequential processes of ethanol extraction, HP-20 column chromatography, ethyl acetate extraction, silica gel column chromatography, and crystallization.

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Purpose: To determine the shade distribution of varied shades of contemporary resin composites, and to measure the color difference (deltaE*ab) between individual shades of resin composites and the nearest shade tabs, which showed the smallest color difference with each shade of resin composite, in the VITA shade guide.

Methods: Eight light-curing resin composites, with a total of 41 shades, were studied. Color of specimens was measured on a reflection spectrophotometer over a white background.

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The effects of tributyltin acetate (TBTA) on dopamine biosynthesis and L-3,4-dihydroxyphenylalanine (L-DOPA)-induced cytotoxicity in PC12 cells were examined. TBTA at concentrations of 0.1-0.

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(1R,9S)-beta-hydrastine (BHS) decreases the basal intracellular Ca(2+) concentration ([Ca(2+)](i)) in PC12 cells.(5) This study examined the effects of (1R,9S)-BHS on [Ca(2+)](i) in PC12 cells. (1R,9S)-BHS at 10-100 microM in combination with a high extracellular K+ level (56 mM) inhibited the release of dopamine in a concentration-dependent manner with an IC(50) value of 66.

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Tributyltin chloride (TBTC) at concentrations of 0.5-1.0 microM inhibits dopamine biosynthesis in PC12 cells.

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The present study was performed to determine whether the effects induced by GABA(B) receptor-acting drugs would be related with the alteration in GABA(B) receptor expression in the hippocampus using Mongolian gerbil, a genetic epilepsy model. The distribution patterns of both GABA(B) receptor 1A/B and GABA(B)receptor 2 immunoreactivities were similarly detected in the hippocampi of normal and seizure-prone gerbils. Following baclofen (GABA(B) receptor agonist) or phaclofen (GABA(B) receptor antagonist) treatment, GABA(B) receptor immunoreactivities were decreased or increased by dose-dependent manners, respectively.

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In the present study, the expression of Na(+)-K(+) ATPase in the gerbil hippocampus associated with various sequelae of spontaneous seizures were investigated in order to identify the roles of Na(+)-K(+) ATPase in the epileptogenesis and the recovery mechanisms in these animals. The population of Na(+)-K(+) ATPase immunoreactive neurons and Na(+)-K(+) ATPase immunodensity were significantly lower in the pre-seizure group of SS gerbils than those in SR gerbils. At 30-min postictal, the Na(+)-K(+) ATPase immunoreactivity was significantly elevated in the hippocampal complex.

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In the present study, we focused upon expression and changes of endogenous insulin-like growth factor-1 (IGF-1) in the hippocampus of the Mongolian gerbil after ischemic insult. In sham-operated animals, IGF-1 immunoreactivity was absent from the hippocampus. IGF-1-immunoreactive (IR) neurons were detected at 12 h and 1 day after ischemic insult.

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In the present study, we investigated site-specific expressions of GABA(A) and GABA(B) receptor subunits in the seizure-sensitive (SS) and seizure-resistant (SR) gerbil hippocampus to elucidate the function of the gamma-aminobutyric acid (GABA) receptor in seizure activity in this animal. There were no differences of the immunoreactivities of GABA(B) receptor and some GABA(A) receptor subunits (alpha3, alpha4, pan beta and delta) in the hippocampus between SR and SS gerbils. The alpha1 subunit expression was mainly detected in interneurons of stratum radiatum and hilar region of dentate gyrus in the SR gerbil.

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In the present study, the P(2)X(7) receptor expression in the gerbil hippocampus and GABA-mediated responses of its expression was investigated in order to identify the roles of the P(2)X(7) receptor on seizure activity and recovery mechanisms. P(2)X(7) receptor immunoreactivity in seizure-resistant (SR) gerbils was similar to that in pre-seizure group of seizure-sensitive (SS) gerbils. The administration of baclofen, a GABA(B) receptor agonist, P(2)X(7) receptor immunoreactivity was decreased in the mossy fiber, compared with that of non-treated gerbils, whereas treatment with phaclofen, a GABA(B) receptor antagonist, elevated P(2)X(7) receptor expression.

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Differences in expression of N-methyl-D-aspartate (NMDA) receptor and voltage gated Ca2+ channels (VGCC) in the gerbil cerebellum were investigated to identify routes of Ca2+ influx that may be involved in Purkinje cell damage. Immunodensities of NR1 and NR2A/B were the same in seizure resistant (SR) and seizure sensitive (SS) gerbils. However, both P/Q type (alpha1A) and L2 type (alpha1D) VGCC levels were higher in the Purkinje cells of SS gerbils than in those of SR gerbils, whereas N type (alpha1B) and L1 type (alpha1C) VGCC levels were similar in the two groups.

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To identify the effects of vigabatrin (VGB) on the metabolism of pyridoxal 5'-phosphate (PLP) in the seizure prone gerbil hippocampus, we conducted a chronological and comparative analysis of pyridoxal kinase (PLK) and pyridoxine-5'-phosphate oxidase (PNP oxidase) expression. In the VGB treated animals, PNP oxidase immunoreactivity was reduced, although the distribution and immunodensity of PLK were unaltered, as compared with control animals. In a Western blot study, the densities of PNP oxidase immunoreactivities in VGB treated animals were found to have decreased significantly.

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We investigated the distribution of somatostatin receptors (SSTs) in the hippocampi of SR (seizure-resistant) and SS (seizure-sensitive) gerbils in order to characterize the alterations in SST expressions induced by seizure activity. SST2A immunodensity in the hippocampus of SS gerbils was lower than that of SR gerbils, though its localization in the hippocampus was similar in both SR and SS gerbils. SST3 immunodensity in the hippocampus of SS gerbils was lower than in SR gerbils.

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